ANTHEAX. 285 



When rubbed up with the blood or aqueous or vitreous 

 humor of an ox, and placed in a well-closed glass vessel, there 

 quickly ensued an odour of putrefaction ; the bacilli disappeared 

 after twenty -four hours without the fibres enlarging, and lost 

 their infective power. That their death was due to the absence 

 of oxygen was shown by placing a drop of blood infected by the 

 bacilli under the microscope. Examined by the micro-spectro- 

 scope it gave the bands of oxy-hgemoglobulin ; the fibres in this 

 drop increased four or five times in length in three hours, but 

 after that time the oxygen was clearly used up, as the presence 

 of the absorption band of reduced hsemoglobulin proved. From 

 this moment the growth of the bacillar fibres ceased, although 

 true putrefaction had not set in. . 



When the spores and bacilli are separated from the blood by 

 filtration, the blood is said to be rendered innocuous ; and when 

 pregnant animals become affected, or have been inoculated, 

 the blood of the foetus does not become diseased, and other 

 creatures can be inoculated with it and suffer no harm, the 

 intervening membranes acting the part of a filter. The bacilli 

 also disappear in liquids in the presence of carbonic acid, and 

 the blood soon loses its specific property. 



This proves that, to live and grow, the bacilli require to 

 absorb oxygen and give out carbonic acid ; hence they are what 

 M. Pasteur terms " aerobic." If the fiuid which contains them 

 begins to putrefy they are destroyed, not only by being deprived 

 of oxygen, but by being brought into contact with other 

 organisms, such as the microbes of putrefaction, in the presence 

 of which, and of all other low forms of organisms, they either do 

 not develop at all, or develop with great difficulty. The 

 organisms of putrefaction are not aerobic, and cease to move 

 when brought in contact with oxygen ; disappear, being trans- 

 formed into refracting corpuscles, which in a suitable soil become 

 motile, and multiply . with extreme rapidity in a putrefying 

 fluid. If an animal be inoculated with it when in this condition, 

 it does not die of anthrax, but of septicaemia, the symptoms of 

 which, when produced in guinea-pigs with the blood of a horse 

 which had been dead of cliarbon twenty-four hours, and which 

 contained the bacteria of putrefaction as well as some bacilli, 

 and with the blood of a cow which had been dead forty-eight 

 hours, and which contained a preponderating quantity of motile 



